The present invention relates to a monocrystal ingot attitude-adjusting/surface-grinding/conveying apparatus for adjusting the attitude of a monocrystal ingot in such a manner that the grinding rotation center of the monocrystal ingot is made coincide with the center of the clamp rotational shaft of a surface grinding device, grinding the surface of the monocrystal ingot to form a cylindrical shape by the surface grinding device and conveying the monocrystal ingot after it has been ground
Monocrystal ingots manufactured by a CZ method or an FZ method are respectively made to be in the form of a cylinder by the following processes
(1) The conical two end portions of the monocrystal ingot are cut off in a direction perpendicular to its axis so that the monocrystal ingot is made to be in the form of a substantially cylindrical shape
(2) The monocrystal ingot placed on a carrier is manually carried before an operator holds it so as to set it to the rotational clamp shafts of a rotating device While manually rotating the monocrystal ingot, the quantity of the deviation of the rotation center of the monocrystal ingot from the rotation center of the rotational clamp shafts is intentionally determined depending upon the sense of an operator for the purpose of making the diameter of the ground monocrystal ingot to be the maximum diameter. The operator knocks the surface of the monocrystal ingot with a hammer so as to correct the above-described deviation.
(3) In this state, the rotational clamp shafts are abutted against the end surfaces of the monocrystal ingot with large force. Subsequently, the monocrystal ingot is rotated, and a grindstone is translated while being abutted against the surface of the monocrystal ingot by a grindstone moving device. As a result, the side of the monocrystal ingot is ground to form a cylindrical shape.
Hitherto, the working efficiency has been insufficient since the process (2) has been performed by an operator.
In order to automate the above-described process, it might be considered feasible to employ an apparatus arranged in such a manner that a robot for loading/unloading the monocrystal ingot is provided for each of the monocrystal ingot grinding devices and a monocrystal ingot conveying device is provided along with the above-described robots.
However, a problem arises in that the size of the apparatus becomes too large, causing the cost of equipment to also be enlarged excessively. Furthermore, the required space becomes too large
Furthermore, since the above-described quantity of the deviation has been detected by the sense of the operator, the above-described two centers have not been made accurately coincide with each other. Therefore, an excessively large quantity of the surface layer of the monocrystal ingot has been undesirably ground, causing a large economical loss to be generated.
In order to automate the above-described process and as well as to make the two centers accurately coincide with each other, it is necessary to use a monocrystal ingot attitude adjusting device having a pair of hands for holding the monocrystal ingot, the monocrystal ingot attitude adjusting device being capable of adjusting the position of each of the hands The monocrystal ingot attitude adjusting device may further include two X-Y stages for moving the hands independently in a vertical plane. However, another problem takes place in this case in that the width of the monocrystal ingot attitude adjusting device cannot be reduced satisfactorily. What is even worse, the grinding rotation center of the monocrystal ingot cannot be made accurately coincide with the rotation center line of the rotational clamp shaft That is, two operational steps must be performed in order to make the grinding rotation center line to parallel the rotation center line of the rotational clamp shaft Furthermore, two operational steps must be performed for the purpose of making the above-described two center lines coincide with each other. However, if the motors for respectively operating the two hands are rotated for the same time, the two center lines cannot be accurately made coincide with each other because of the difference between the stoppage accuracies of the two motors and the mechanical dimensional errors between the two hands. Therefore, if the two hands are individually operated, excessively large force is applied to undesirably strain the monocrystal ingot